Renowned shipowner John Fredriksen is now worth close to NOK 200bn ($20.3bn) after shares in tanker and gas companies rose sharply.

An investigation by Norway's Finansavisen has calculated the worth of the London-based tycoon’s public and private investments to come up with the figure.

Fredriksen and daughters Cecilie and Kathrine Astrup Fredriksen saw their fortunes boosted by rises in the stock and property markets, but shipping and offshore continued to be the mainstay of their empire.